Depends You could have property_id, user_id, value(string) 1 (assume age), 1213, 60 2 (gender), 1213, female or property_id, user_

Depends You could have property_id, user_id, value(string) 1 (assume age), 1213, 60 2 (gender), 1213, female or property_id, user_id, value_str, value_int 1 (assume age), 1213, null, 60 2 (gender), 1213, female, null or have a mapping in the application to get the type of the property. Plenty of ways to handle it.